Fix some more print() format errors.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 959689e..f701ab6 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -613,7 +613,7 @@
 		return NULL;
 	}
 
-	debug ("   kernel data at 0x%08lx, len = 0x%08lx (%d)\n",
+	debug ("   kernel data at 0x%08lx, len = 0x%08lx (%ld)\n",
 			*os_data, *os_len, *os_len);
 
 	return (void *)img_addr;